As a conventional general linear guide apparatus, for example, the one shown in FIG. 14 is known.
The linear guide apparatus shown in FIG. 14 is provided with a guide rail 101 which extends in the axial direction and a slider 102 which straddles the guide rail 101 capable of moving relatively in the axial direction.
The two side surfaces of the guide rail 101 are formed with rolling element rolling grooves 103 which extend in the axial direction. The slider body 102A of the slider 102 is formed at the inner surfaces of two sleeve parts 104 with rolling element rolling grooves 107 which face the rolling element rolling grooves 103. Further, between each two facing rolling element rolling grooves 103 and 107, as one example of the rolling elements, a large number of balls B are rollably loaded. Through rolling of these balls B, the slider 102 can move on and relative to the guide rail 101 in the axial direction.
Along with this movement, the balls B interposed between the guide rail 101 and the slider 102 roll and move to the end parts of the slider 102. However, in order to continuously make the slider 102 move in the axial direction, these balls B have to be endlessly circulated.
For this reason, the sleeve parts 104 of the slider body 102A are formed therein with rolling element passages 108 which run through the axial direction, and both ends of the slider body 102A are secured with substantially U-shaped end caps 105 through for example screws 112 or other securing means. This end caps 105 are formed with direction changing channels 106 bent in semi-circular shapes connecting the two rolling element rolling grooves 103 and 107 and the rolling element passages 108, whereby rolling element endless circulation raceways are formed. Note that, in FIG. 14, reference numeral 111 indicates side seal members (rubber seal members) secured together with the end caps 105 to the end faces of the slider body 102A via screws 112 etc., reference numeral 110 indicates a tap hole for a screw 112 formed at an end face of the slider body 102A, reference numeral 113 indicates a greasing nipple, and reference numeral 114 indicates a bolt hole for securing the guide rail 101.
The side seals 111 are each made in substantially U-shape in the same way as the end caps 105, their inner circumferences are made seal surfaces which slide against the guide rail 101, and the seals are formed by steel sheets on which rubber is baked.
In this regard, in a linear guide apparatus used for a machine apparatus like a machine tool in which cutting dust and other foreign matter is generated, the seal by the above-mentioned side seal members 111 is not sufficient and the lubrication conditions become severer.
For this reason, the linear guide apparatus shown in FIG. 15 for preventing the entry of foreign matter to the inside of the slider and thereby prevents early wear or breakage (see Patent Document 1), has been proposed.
In the linear guide apparatus shown in FIG. 15, the end parts of the slider 102 (actually, the end caps 105) in the axial direction are provided with lubricant feed members 115. At the outer surface sides of the lubricant feed members 115, pluralities of seal members arranged and overlaid in the axial direction of the slider 102 are attached. The pluralities of seal members are interposed between hard seal members 117 arranged at the outer most sides in the axial direction of the slider 102 and the lubricant feed members 115. The pluralities of seal members are provided with soft seal members 121, 111, and 120, each having hardness lower than that of the hard seal members 117, and having mutually different seal performances.
Further, as a lubricating device of a guide apparatus for supplying the minimum extent of lubricating oil to the sliding surfaces of a guide member and moving member of a linear guide apparatus in proportion to the relative movement between the guide member and the moving member, for example, the one shown in FIG. 16 is known (see Patent Document 2).
The linear guide apparatus shown in FIG. 16 is provided with a guide rail (guide member) 201 and a moving member 202 slidably attached to the guide rail 201 and moves along the guide rail 201. The guide rail 201 has rolling grooves 205 which extend in the axial direction at the two side parts of the top surface and the top parts of the two side surfaces. The moving member 202 is provided with a body 203 and end caps 204 secured to the two end parts of the body 203. The body 203 is formed with grooves 206 constituting load raceways and grooves 207 which form return raceways, while the end caps 204 are formed with raceways 208 which connect the grooves 206 and the grooves 207. When the body 203 and the end caps 204 are connected, the moving member 202 is formed with four endless raceways. Each endless raceway is provided with a large number of balls 209 which form an aligned state.
Further, one end cap 204 is provided with a lubricating device 210 for supplying lubricating oil to the sliding surfaces 215 of the rolling grooves 205 of the guide rail 201 and of the balls 209 of the moving member 202.
The lubricating device 210 has: a case 211 secured to the end cap 204 so that its open end comes closer to a sliding surface 215 of the guide rail 201; a flexible sliding member 212 supported in the case 211 so that one end slides against the sliding surface 215 and segmenting the inside of the case 211 into two chambers; a lubricating oil storing member 213 arranged at a position of being pressed by the flexible sliding member 212 in the case 211 for supplying the lubricating oil to the sliding surface 215; and a seal piece 206 secured to the wall surface of the chamber in which the lubricating oil storing member 213 in the case 211 is arranged so that one end slides against the sliding surface 215.
Further, if the moving member 202 moves in the arrow A direction in FIG. 16, the flexible sliding member 212 of the lubricating device 210 slides over the sliding surface 215 and deforms in a direction coming closer to the lubricating oil storing member 213. If the flexible sliding member 212 deforms, the flexible sliding member 212 pushes against the lubricating oil storing member 213 and the lubricating oil stored in the lubricating oil storing member 213 is supplied to the sliding surface 215 in only an amount of the minimum extent proportional to the amount of motion of the moving member 202.
Next, when the moving member 202 reaches the end position of the guide rail 201, and the moving member 202 turns around and moves in the arrow B direction in FIG. 16, the flexible sliding member 212 deforms in a direction separating apart from the lubricating oil storing member 213, a clearance is formed between the flexible sliding member 212 and the lubricating oil storing member 213. Accordingly, an amount of lubricating oil corresponding to the amount supplied by the lubricating oil storing member 213 is refilled to the lubricating oil storing member 213.